The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus provided with a charger for electrostatically charging an image carrier.
There are conventionally known image forming apparatuses that are provided with a charging roller (charger) for electrostatically charging a photosensitive drum (image carrier), a developing device including a developing roller for supplying the photosensitive drum with toner, and a voltage application unit for applying a voltage to the charging roller and to the developing roller. A developing bias having an AC voltage superposed on a DC voltage is applied to the developing roller, and a charging bias including a DC voltage is applied to the charging roller.
There are also known image forming apparatuses in which an electric shield formed by an electrically conductive member is arranged between a charging roller and a developing sleeve (developing roller). In such image forming apparatuses, an AC component in a developing bias applied to the developing sleeve can be prevented from adversely affecting the charging roller. It is thus possible to suppress uneven charging of the photosensitive drum.